This invention is concerned with shoe supports for use in a machine for operating on side wall portions of a lasted shoe upper and with machines for operating progressively along side wall portions of a lasted shoe upper.
It will be appreciated that, in a case of operating upon side wall portions of a lasted shoe upper, it is necessary to ensure that the shoe the side wall portions of which are to be operated upon is held in such a manner that the side wall portions are left exposed and no portion of the shoe support will prevent access to the side wall portions by the operating tool.
One shoe support, which is described as for use in a machine for roughing marginal portions of shoe bottoms, is disclosed in GB-A No. 1431127, which shoe support comprises a last pin for supporting, bottom uppermost, a shoe last on which a lasted shoe upper is carried, a toe support for supporting the toe end of a lasted shoe supported by the last pin, and means for urging the toe support upwardly, the arrangement being such that in loading a shoe on the shoe support the last is first placed on the last pin, whereafter relative movement, in a direction lengthwise of the shoe bottom, is effected between the last pin and the toe support, which movement is terminated when the toe is engaged by an abutment associated with the toe support, whereupon the toe support is raised into engagement with the toe end of the shoe, and by such engagement, urges the shoe to tilt about the last pin until the last pin engages the periphery of the last pin hole formed in the last, thereby locking the shoe in position in the shoe support. In this way, it will be appreciated, the shoe is thus held in position merely by the counter-action of the last pin and the toe support.
In the particular machine described in the aforementioned specification the heightwise position of the tool in relation to the shoe is determined by the engagement with the shoe bottom of a stop associated with the tool; in the particular case the stop is in the form of a fork the "prongs" of which are disposed at opposite sides of the tool. In other machines (see e.g. EP-A No. 0043645), however, the heightwise position of the tool relative to the shoe bottom is determined under computer control, to which end it is of course necessary to maintain certain portions of the shoe bottom, e.g. the heel seat and the toe end each at known height datum. In the case of the aforementioned shoe support, clearly the height of the toe end of the shoe will depend essentially upon the amount of heightwise movement which has to be effected to achieve the binding effect of the last pin hole on the last pin, so that the heightwise position of the toe end of the shoe cannot be predetermined. Moreover, the heightwise position of the heel seat of the shoe will, albeit to a lesser degree, also be dependent upon the amount of such heightwise movement of the toe end of the shoe.